- Travel Distance to Exits refers to the maximum allowable distance a building occupant must travel from any point within a space to reach the nearest exit. This distance is regulated to ensure safe and efficient egress during an emergency.
- The Building Standard Law of Japan (BSL Article 119) sets travel distance limits to ensure safe evacuation in assembly occupancies. Travel distances are regulated based on fire protection measures and building configuration.
- IBC (USA): Section 1017.2, which defines travel distance limits based on sprinklered vs. non-sprinklered buildings.
- BSL (Japan): Article 119, which sets fixed travel distance limits depending on fire protection and building type.
Maximum Allowable Travel Distance to Exits
| Code | Non-Sprinklered Buildings | Sprinklered Buildings |
| IBC (Section 1017.2 – USA) | 150 feet (45.72 m) | 200 feet (60.96 m) |
| BSL (Article 119 – Japan) | 30 meters (98.4 feet) | 50 meters (164 feet) |
- IBC allows longer travel distances than BSL, especially for sprinklered buildings (200 feet vs. 164 feet).
- BSL enforces a stricter maximum travel distance for non-sprinklered buildings (30 meters / 98.4 feet), while IBC allows up to 150 feet (45.72 m).
- IBC provides more flexibility for fire-protected buildings, while BSL maintains more conservative limits.
Adjustments Based on Fire Protection & Building Features
| Code | Impact of Sprinkler Systems | Impact of Open-Plan Design |
| IBC (1017.2) | – Allows 200 feet (60.96 m) max in sprinklered buildings. – Requires shorter travel distances in non-sprinklered structures. | – Travel distances can be extended if the building has multiple exits and direct exterior access. |
| BSL (Article 119) | – Allows 50 meters (164 feet) max in sprinklered buildings. – Does not allow travel distance extensions based on fire-rated corridors. | – Travel distances are strictly limited to 30m/50m, even if the building is open-plan. |
- IBC allows greater flexibility in sprinklered buildings and open-plan layouts, while BSL enforces strict maximums regardless of building configuration.
- BSL does not allow travel distances to be extended based on fire-rated corridors, whereas IBC permits extended distances in some cases.
Special Considerations for Egress & Evacuation Efficiency
| Code | Corridor & Exit Layout Considerations | Impact on Large Assembly Spaces |
| IBC (1017.2) | – Travel distances may be extended when additional safety features (such as emergency lighting and multiple exit routes) are present. | – Larger venues may require additional exits to ensure compliance with max travel distances. |
| BSL (Article 119) | – Travel distances are fixed and do not increase based on corridor configurations. | – Additional exit locations may be required for large theaters or sports arenas. |
- IBC allows adjustments based on corridor layouts and fire safety enhancements, whereas BSL applies fixed maximums.
- BSL may require more exits in large assembly spaces due to its shorter maximum travel distances.
Key Differences & Considerations
| Aspect | IBC (1017.2 – USA) | BSL (Article 119 – Japan) |
| Max Distance (Non-Sprinklered) | 150 feet (45.72 m) | 30 meters (98.4 feet) |
| Max Distance (Sprinklered) | 200 feet (60.96 m) | 50 meters (164 feet) |
| Impact of Sprinkler Systems | Allows increased distance in sprinklered buildings. | Allows some increase, but still stricter than IBC. |
| Open-Plan Layout Adjustments | Travel distances can be extended if multiple exits are available. | Fixed travel distances apply, regardless of layout. |
| Flexibility for Large Venues | Larger assembly spaces can extend travel distances with proper exit placement. | Additional exits may be required to comply with strict distance limits. |
Recommendations for Improvement
| Issue | IBC Recommendation | BSL Recommendation |
| Travel Distance Limits in Large Assembly Buildings | Increase max travel distance to 250 feet (76.2 m) for fully sprinklered theaters and stadiums. | Increase 50m max travel distance in sprinklered buildings to 60m (197 feet) for open-plan spaces. |
| Stricter Distance Control for Non-Sprinklered Buildings | Reduce non-sprinklered max distance to 140 feet (42.67 m) for better consistency with global standards. | Allow some flexibility in non-sprinklered buildings if additional fire protection measures are in place. |
| Adaptability for Open-Plan Layouts | Implement clearer guidelines for exit placement adjustments based on travel distance. | Allow extended travel distances if multiple visible exits exist within the space. |
Summary
- IBC allows longer travel distances than BSL, especially in sprinklered buildings (200 ft vs. 164 ft).
- BSL enforces stricter distance limits for non-sprinklered buildings (98.4 ft vs. IBC’s 150 ft).
- IBC permits extended travel distances based on open-plan designs and exit visibility, while BSL maintains strict limits.
- BSL requires more exit placement planning in large assembly venues due to its shorter travel distance limits.
- IBC offers more adaptability for fire-protected buildings, whereas BSL applies fixed distance controls.